Electric water heaters for family residences generally include two heating elements each of which is controlled by a separate thermostat which turns the heating element on when the water temperature is below a selected level, e.g. 100.degree. F., and turns the element off when the water temperature reaches an upper selected level, e.g. 130.degree. F. One element is located in the upper portion of the water reservoir and the other in the lower portion of the water reservoir. Cold water is fed into the bottom of the reservoir and hot water leaves from the top of the reservoir.
In the normal operation the two elements are joined in a circuit in which the upper element is used first in order to maintain a supply of hot water in the upper portion of the reservoir, and when the upper thermostat senses the temperature of 130.degree. F. it turns off the upper element and closes the circuit including the lower element which heats the water in the lower portion of the reservoir. As hot water is used the lower element is turned on to heat the incoming cold water, with the result that the lower element is turned on and off many more times than the upper element and thereby is more likely to burn out sooner than the upper element. When it does burn out, the upper element assumes all of the heating load and the owner rarely knows that the lower element is not functioning until both elements are burned out. In the meantime there may be a considerable waste of power by shorting of the lower element which is costly to the homeowner.
It is an object of this invention to provide a system for testing the operability of heating elements in a water heater. It is another object of this invention to provide such a system that is easily used by anyone, young or old, blind, or deaf. Still other objects will become apparent from the more detailed description which follows.